The immediate objective of the proposed research is to ascertain whether or not the priviosly demonstrated enhancement of urinary bladder cancer by normal rat urine is due to a specific substance(s). To attain this goal, the major specific aims are: 1. to isolate, purify and eventually characterize the ornithine-decarboxylase (ODC)-inducing substance(s) in urine which we designate as urinary growth factor (UGF). Our particular attention will be directed to determine if the UGF(s) represents or resembles the epidermal growth factor, 2. to test UGF(s) on its ability to stimulate DNA synthesis in the heterotopically transplanted rat urinary bladder (HTB) and a squamous cell carcinoma cell line 804G, and 3. to test UGF(s) on its ability to enhance tumorigenicity in HTB's. Our overall goal will be to best 1) if the biological characteristics of UGF can be enhanced by its enzymic cleavage, and 2) if tumor enhancement can be blocked by simultaneous use of an ODC inhibitor or by antibody made against UGF.